During 2005–2006, these researchers surveyed a random sample of New Zealand primary care practices, with over-sampling of practices serving indigenous children, in this investigation into primary care factors associated with immunisation coverage. Practice immunisation coverage was defined as the percentage of registered children from 6 weeks to 23 months old at each practice who were fully immunised for age. A median of 71% of registered children at each of the 124 participating practices was fully immunised. In multivariate analyses, higher immunisation coverage was achieved by practices with no staff shortages (median practice coverage 76% vs 67%; p=0.004) and where doctors were confident in their immunisation knowledge (72% vs 67%; p=0.005). Coverage was lower if the children’s parents had received information antenatally, which discouraged immunisation (67% vs 73%; p=0.008). Coverage decreased as socio-economic deprivation of the registered population increased and as the children’s age and registration age increased.
